Ring oven with revolving hearth



April 17, 1928.

- L. HONIGMANN ET AL mm OVEN WITH REVOLVING, 'HEARTH INVENTORS Fi'led June 2, 1926 AId 'yMQ MM/IW 4 5 .separaton.

, which isarranged the jet nozzle.

' larly Patented Apr. 17, 1928.

LUDWIG HONIGMANN,

OF BAD TOLZ AND FRIEDRICH BARTLING, OF IUNIOH,

GERMANY.

RING QVEId' WITH REVOLVING HEABTK.

Application filed June 2,

Our Patent No. 1,634,027, issued June 28, 1927, relates to a ring oven with revolving hearth for the treatment by heatof pulvcrulent granular or like material which at the charging point is applied in the form of a thin layer to the revolving hearth while the forward radial edge of the charging box wipesofi the excess material from the hearth. The product treated by heat is'then sucked away at the delivery oint together with the gases from the oven 0 amber and these gases are then conveyed fter the separation of the pulverulent products-back intothe oven.

The object of this invention is a particuuseful construction of this oven the aim being first of all to enable at the outset only a small part of the oven gases to be split oil as delivery means and to be convcyed in a separate circulating "current through the delivery In order to attain this, use is made ac cording to this invention of a' discharge device wherein a closed pipe conduit, built into which is a dust separator and a circulating pump, is provided with ajet-like interrup tion which is directly livery point of the ring oven so that the gas current carries ofi the oven material to be carried out.

In order to safeguard the separation from the bulk of the oven gases, above the discharge point, a closed box beneath the which the ring hearth substantially The suction pipe of the circular current conduit terminates by preference in a lateral Wall of which, situated in the direction of the advancing ring,'is providedwith sieve-like perforations opposite to which is arranged the nozzle opening of the pressure pipe. This has for its result that a jet of working gas is caused to passdirectly over the discharge point of the hearth which jet,

in the manner of a jet pump, carries away the dust-like material located beneath. Due to the particular arrangement of the jet nozzle a direct blowing on and consequential whirling of the material on the hearth is counteracted. The'discharge head may be closed below, by a solid bottom or may be open and operate so closely above the revolving health that the latter closes the or of a spring on guide.

point and the dust situated above the de-' there is provided open underside. ofis displaced, and in closed head, the

1926,ser1al no. 118,286, and in Germany June a, 1925.

head relatively tightly and thus substantial- B6 ly replaces the bottom. The head of the suction pipe may, according to this invert. tion, be connected to the suction conduit by flexible means for exam le a metal hose or aflexible tube. It, gli es positively under the influence, for example, ofits own weight ways of the hearth, being prevented from being carried alo by appropriate means. The last mentione arrangement may usefully be applied also '86 to the charging point where, according to the previously mentioned patent, the lower edge of the charging hopper wipes-over protruding ribs, ledges or like projection on the hearth surface between which the material is introduced in appropriate grooves or like cavities. The object of this arrangement, is

a wiping offof the charged material by the charging hopper itself'in order to counteract accumulations of the material on the hearth and to distribute it in a thin layer. The use of this arrangement for regulating the layer presents difiicultiesin so far as it presupposes an accurately uniform circulation of the hearth in a horizontal plane which of course is attainable only within certain limits andmoreover because the considerable heat of the oven hearth and other parts thereof are liable to; changetheir dimensions. For this reason theregulation of the thickness, of thelayer by means of this device can be attaiiled only in a more or less general way. In cases in which the materially finer regulationis desired the requisite aid is to be created by the-present invention. The device forming the subject of the aforementioned patent renders it more parv ticularly impossible to charge different thicknesses and this again is to be rendered possible by this invention, the idea being 95 that, for the perfection of the charging device serving as a layer regulator, it should be possible to enable an automatic precise adjustment of the charging box relatively to the hearth also in such cases in which the hearth does not rotate precisely in a hori- Zontal plane. or is subject to variations during the Working. Again an arbitrary regulation of the thickness of the layer should be possible, .taking into account various 105 working conditions, materials or the like.

' Accordingly a further characteristiefeature of the lnvention resides in the coupling,

. charging box with the stationary charging pipe by flexible means and to cause it to wipe over the guide ways of the hearth by positive pressure while preventing it from being carried along with the rotating hearth by appropriate arrangement. The weight of the charging box, which per se is not prevented from an automatic adjustment by any rigid connection, permits the box to wipe on the guide ways of the hearth even if the latter deviates from its horizontal 1'0- tary plane. I

In order, in addition, to enable the thickness of the layer to be arbitrarily varied, the charging box according to this invention is provided with a vertically adjustable slide operating between the guide ways.

In a preferable construction the arrangement is to be such that the surface of the ring hearth is provided with two ring shaped marginal ledges over which the edges of the charging box are caused to wipe and between which the surface of the ring hearth is provided with teeth, roughenings or the like for the engagement of the material charged thereon. Instead of depressing the charging box on to the hearth by its own weight use may of course be made also of any other device, for example, of springs.

A constructional form of the invention is illustrated by wayof example in the accompanying drawings in which Fig. 1 represents a section of the ring "hearth in the direction of its advance at the discharge point,

Fig. 1 is a fragmentary top plan, on a reduced scale, of the construction shown in Fig. 1, with the addition of certain ele- 1 ments to complete the circulating conduit,

Fig. 2 isa sectional view at the charging point and Fig. 3 is a radial section of the oven taken through the charging point.

The oven shown in this constructional form is provided in known manner with a ring shaped flue a covered on top and open at the bottom. The lower opening is bridged by the annular revolving-hearth which moves in the direction of the arrow 6 and is outwardly packed for instance by means of surface of the hearth is provided sand troughs or water charged cooling troughs n,. .-0' (F ig.- 3). .The hearth a is maintained in movement by means of a gear 12. According to the invention the upper with pro jecting guide ways such as marginal ledges 1 between which the surface of the hearth is appropriately cavitated. By preference the surface of the hearth is provided with teeth or is otherwise roughened for a readier engagement of the material thereon.

Arranged at the discharge point A in the oven chamber is a box c which is closed on;

all sides except at the bottom. The open bottom is however obturated by the revolving hearth a moving beneath the same. From above there extends a pressure pipe d and a suction pipe e which are connected, to form a closed circulating conduit, as shown in Fig. 1, in which a circulating gas cur rent is maintained by a blower 1- and a dust separator s of any suitable construction. The suction pipe 0 carries a hollow head f of say square shape which has a relativelygreat weight and is coupled withthe suction pipe 6 by flexible means, for instance a metal hose g. The heavy head f wipes, with its lower closed or open end, over the guide ways on the revolving hearth a -thus adapting itself to any deviations of the hearth from the precisely horizontal position. The

' head is prevented by any appropriate means such as a transverse bar f from being carried along with the hearth. The face it of the head situated in the direction of the hearth advance is perforated .in a sieve-like manner. The pressure pipe 03 has its lower open end bent so as to blow its gas jet directly against the perforated wall h and through same. WVhen the pump is started it sucks from the pipe 6 a certain amount of working gas which thereafter circulates continually through the circulating conduit. The gas flows from the pressure pipe d, the terminal (1 of which may be constricted, in the form of a sharp edge and after crossing the space between the two pipes penetrates through the perforated face It whence it is sucked over to the dust separator. In this action the pulverulent or granular layer of material is completely sucked away from the hearth by the jet action,

The charging device at the charging point B comprises a charging box i of sufficient weight, the edges of which wipe on the marginal ledges 1'. of the hearth. It is prevented from being carried along by the hearth by transverse stop bars 2' or the like. The box is connected by a flexible link, for example a flexible pipe 9 to the charging pipe Z proper, which is stationary. Arranged at one of the broad sides of the charging hopper is a vertically displaceable slide m which projects beyond the lower edge of the hopper and is so shaped as to enter between the guide ledges 1'. By vertical adjustment of the slide m the thickness of the material charged may be regulated at will.

We claim 1. In a ring over for the treatment by heat of pulvei'ulent, granular or like material in which the material at the charging point is charged in the form of a thin uniform layer and at the discharge point sucked away with the oven gases, a revolving hearth, a conduit throu hwhich a portion of the oven gases are diverted past the discharge point to act as a discharging. means,

I ranged immediately above said discharge.

said conduit including a pressure pipehavpoint, a dust separator in said conduit, and a pump also in said conduit.

2. In a ring oven for the treatment by heat of pulverulent, granular or like material in which the material at the charging point is charged in the form of a thin uniform layer and at the discharge point sucked away with theoven-gases, a revolving hearth, a conduit through which a portion ofthe ovengases arediverted past the discharge point to act as a discharging means, said heat of pulverulent, granular or like ma I ing a jet nozzle disposed a conduit having a jet nozzle therein arranged immediately above said. discharge point, a dust separator in said conduit, a pump also in said conduit, and a closed box above said discharge point having an open underside adjacent said hearth and in which said jet nozzle is located.

3. In a ring oven for the treatment 'by heat of ulverulent, granular or like material in which the material at the chargingpoint is charged in the form of a thin uniform layer and at the discharge point sucked away with the oven gases, a revolving hearth, a conduit through which a portion of the oven gases are diverted past the discharge point to act as a dischargin means, said conduit including a pressure pipe having a jet nozzle disposed above said discharge point; and also including a suction pipe having a head in the direction of.revolution of said heart and a dust separator in said conduit.

4. In a ring oven for the treatment by heat of pulverulent, granular or like material in which the material at the charging point is chargedin the form of a thin uni- .form layer-and at the discharge point sucked away with the oven gases, a revolving hearth, a conduit through which a portion.

of the oven gases are diverted past the discharge point to act as a discharging means, said conduit including a ressure pipe hav- Eove said discharge point, and also including a suction pipe having ahead providedwith a perforated side arranged opposite said jet nozzle and facing in the direction of revolution of said "hearth,

'fiexibleineans coupling said head with the remainder of the suction pi e so that said head is caused to wipe over t e adjacent surface of said hearth, and means to prevent 'movement of said head with said hearth.

.5. In a ring' oven for the treatment by terial in which the material at the charging point is charged in the form of a thin uniform layer and at the. discharge point sucked away with the oven gases, a revolving hearth, a conduit through which a plortion of the oven gases are diverted past e dis charge pointto act as a discharging means,

ing a jet nozzle disposed above said disrated side arranged opposite said jet nozzle and facing in the direction of revolution of said hearth, flexible means coupling. said head with the remainder of the suction pipe so that said head is caused to wipe over the adjacent surface of said hearth, means to prevent movement of said head with said earth, a charging pipe, a charging hopper at said charging point wiping over the surface of said hearth as the latter is revolved, flexible means connectin pipe with said chargin opperto permit the latter to engage sai hearth, and means to prevent said charging hopper being carried along with said hearth.

6. In a ring oven for the treatment by heat of pulverulent, granular or like material in which the material at the charging point is charged in the form of a thin uniform layer and at the discharge point sucked away with the oven gases, a revolving hearth, a'condu'it. throughwhich a portion of the oven gases are diverted past the dissaid charging ing a jet nozzle disposeda ve said discharge polnt, and also including a suction pipe having a head providedwith a perforated side arranged opposite-said jet nozzle and facing in the direction of revolution of said hearth, flexible means coupling said head with the remainder of the suction pipe so that said head is caused to wipe over the adjacent surface of said hearth, means to prevent movement of said head with said hearth, a charging pipe, a charging hopper :at said charging point wiping over the surface 0 said hearth as the latteris revolved, flexible means connecting said charging pipe with said charging hopper to permit the latter to engage said hearth, means to prevent said charging hopper being carried along with said hearth, and a vertically adjustable slide for said charging hOJIPBI adapted to extend between the gui ewaysof" said hearth.

7. In a ring oven as claimed in claim wherein a surface of the hearth 'is provided withannular marginal projections for the wiping over of the edges of the charging hopper and. between which the surface of the hearth is roughened for engagement of the material to be carried thereon.

In testimony whereof we/have-signed our names to this specification.

' LUDWIG 'HONIGMANN. FRIEDRICH BARTLING. 

